We prospected that chemically modified miRNA-21 inhibitor based on gold nanoparticles would be as a promising diagnostic and therapeutic platform for breast cancer clinically.
We measured RNA levels of three microRNAs with tumorigenic or angiogenic potential (miR-155, miR-195, and miR-21) in blood samples taken from patients with early breast cancer, both preoperatively and postoperatively.
Using SYBR green real-time quantitative reverse transcription-PCR, we detected the expression of circulating miR-21 in 174 patients with solid cancers and 39 normal control subjects, including breast cancer, esophageal cancer, gastric cancer, colorectal cancer, lung cancer.
Using miRNA-21 in MCF-7 cells (a human breast cancer cell line) as a model, the proposed multifunctional nanosystems not only allow target-cell-specific delivery with the binding affinity of AS1411, but also can track simultaneously the transfected cells and detect intracellular miRNA in situ.
Urinary miRNA expression levels of nine BC-related miRNAs (miR-21, miR-34a, miR-125b, miR-155, miR-195, miR-200b, miR-200c, miR-375, miR-451) from 24 untreated, primary BC patients and 24 healthy controls were quantified by realtime-PCR.
Unexpectedly, three miRs (miR-21, miR-10b and miR-31) demonstrated significantly higher level of expression in biBC vs. uBC (P = 0.0001, 0.00004 and 0.0002, respectively).
To reconstruct the microRNAs-genes regulatory network in breast cancer, we employed the expression data from The Cancer Genome Atlas (TCGA) related to five essential miRNAs including miR-21, miR-22, miR-210, miR-221, and miR-222, and their associated functional genomics data from the GEO database.
To better evaluate the role of miR-21 in tumorigenesis, we transfected breast cancer MCF-7 cells with anti-miR-21 oligonucleotides and found that anti-miR-21 suppressed both cell growth in vitro and tumor growth in the xenograft mouse model.
Thus, we have used an amperometric dual magnetosensor capable of monitoring a miR-21/miR-205 signature to screen for new drugs that restore these miRs to non-tumorigenic levels in cell models of breast cancer and glioblastoma.
This study was designed to compare the responses of breast cancer cells and non-transformed breast epithelial cells to a combined regimen of miR-21 inhibition and radiation.
This study could identify the differentiated miRNAs expression profile in BC and reveal that miR-21 overexpression was correlated with specific breast cancer biopathologic features, such as advanced tumor stage, lymph node metastasis, and poor survival of the patients, indicating that miR-21 may serve as a molecular prognostic marker for BC and disease progression.
This novel HA/CD44-mediated c-Jun signaling pathway and miR-21 production provide a new drug target for the future intervention strategies to treat breast cancer.
This nano-biosensor also demonstrated highly reproducible results in the analysis of blood samples, with recoveries between 94% and 107%, and could be used for early detection of breast cancer by direct detection of the miRNA-21 in real clinical samples without any need to sample preparation, RNA extraction and/or amplification.
This meta-analysis suggests that miR-21 is a potential biomarker for early diagnosis of breast cancer with high sensitivity and specificity, and its clinical application warrants further investigation.
These observations, although a proof of principle finding at this time, show that a combined expression profile of two miRNA (miR-125b/miR-191 and miR-21/miR-191) can discriminate between breast cancer and non-tumor tissue with high specificity and sensitivity.